JWST NIRCam Imaging of NGC 4258: I. Observation Overview
Travis C. Fischer, Nicholas F. Cothard, Omnarayani Nayak, Henrique Schmitt, Erin Smith, and Jason Glenn

TL;DR
This study uses JWST NIRCam imaging of NGC 4258 to investigate AGN-driven shocks and their effects on the interstellar medium, revealing low-velocity shocks and dust grain destruction in the galaxy's disk.
Contribution
First detailed near-infrared imaging of NGC 4258's shock regions with parsec-scale resolution, linking shock properties to AGN feedback mechanisms.
Findings
Shocks in bright radio regions are low-velocity (50-100 km/s).
Multi-phase shocks are indicated by co-spatial [Fe II] and H$_2$ emission.
PAH emission is weaker or absent in shock-excited regions.
Abstract
We present James Webb Space Telescope (JWST) NIRCam imaging of the nearby Seyfert 1.9 galaxy NGC 4258, which hosts strong star formation regions as well as an anomalous jet-like radio structure that extends through a significant portion of its disk. This galaxy provides a unique environment to study Active Galactic Nucleus (AGN)-driven shocks and their impact on the interstellar medium (ISM) as its proximity allows for narrow-band observations of various near-infrared tracers sensitive to multiple levels of shock and radiative excitation: [Fe II] (1.64 m), Pa (1.87 m), H (2.21 m), 3.3 m polycyclic aromatic hydrocarbon (PAH) emission, Br (4.05 m), and Pf (4.66 m), allowing us to trace shocks with parsec-scale resolution. Comparing these near-infrared observations with available ultraviolet, optical, radio, and X-ray imaging, we…
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